import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import javax.annotation.concurrent.GuardedBy;
-import org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType;
import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
import org.opendaylight.controller.cluster.datastore.identifiers.TransactionIdentifier;
import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;